1. Technical Field
The present invention relates to a liquid ejection control apparatus and the like controlling a liquid ejection device which ejects a liquid in a pulse form by using a piezoelectric element.
2. Related Art
There is a technique of cutting a cutting target object by ejecting a liquid in a pulse form. The liquid ejected in a pulse form is a liquid jet flow which is ejected from a nozzle in a pulsating manner, and is referred to as a “pulsed liquid jet” as appropriate in the present specification.
A pulsed liquid jet may be variously applied, and, for example, JP-A-2005-152127 has proposed a technique in which the pulsed liquid jet is used for surgery in a medical field. In this case, a cutting target object is living tissue, and a liquid is physiological saline.
As one of the mechanisms generating a pulsed liquid jet, there is a mechanism using a piezoelectric element. The mechanism applies a pulsed drive voltage to a piezoelectric element so that the piezoelectric element generates instantaneous pressure in a working fluid (liquid), and thus ejects the liquid in a pulse form. Thus, the strength of the pulsed liquid jet is changed by controlling a drive voltage applied to the piezoelectric element. Therefore, there may be a technique in which a characteristic value of a drive voltage applied to a piezoelectric element, for example, the amplitude (which is voltage amplitude and can be said to the magnitude of the drive voltage) of a drive voltage waveform is indicated by using an operation portion such as an operation dial or an operation button, and thus the strength of a pulsed liquid jet is changed.
However, it has been found that, even if the characteristic value of the drive voltage indicated by the operation portion is changed, there is a case where a cutting aspect such as a cut depth or a cut volume of a cutting target object may not be changed as intended by a user. As will be described later in detail, it has been found that, for example, even if the user changes the voltage amplitude to twice or four times, or a half or a quarter, a cut depth or a cut volume is not necessarily changed in proportion thereto. In a case where a pulsed liquid jet is used for surgery, there may be a problem in that working corresponding to an operator's operation sense is not performed.
On the other hand, if an ejection cycle of the pulsed liquid jet is variable, a cut depth or a cut volume per unit time can be changed, and thus it is possible to adjust speed for cutting a cutting target object. However, if the ejection cycle is changed, a shape of a drive voltage waveform is changed, and thus the strength of a liquid jet corresponding to a single pulse may be changed. As a result, a cut depth or a cut volume related to a pulsed liquid jet corresponding to a single pulse is changed before and after an ejection cycle is changed, and thus a cutting speed proportional to an ejection frequency as intended by a user may not be obtained even if an ejection cycle is shortened, that is, an ejection frequency is heightened.